Tangential rolling read

ABSTRACT

A tangential rolling head with a basic body including means for loading it in a machine tool, two two-armed levers pivotally supported about a common axis of the basic body one lever arm of which is traversed by a formed-type roll and the other lever arm of which is traversed by a spindle which has a circumferential annular groove, a sheet metal element which has a forked portion and a fastening portion wherein the forked portion engages the annular groove and the fastening portion is adapted to be fastened in a recess of the basic body by means of a pin, characterized in that the sheet metal element is rigidly formed and is supported in the recess on the two sides by means of disc springs slid onto the pin.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] Not Applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

[0002] Not Applicable.

BACKGROUND OF THE INVENTION

[0003] Tangential rolling heads have two molding rolls which arerotatably supported at the ends of lever arms. The lever arms areadapted to be pivoted about a common axis of a basic body in order tovary the spacing between the molding rolls. The basic body is providedwith means for loading it into a machine tool with those means usuallyhaving a shank which laterally projects from the basic body. Theworkpiece is rotatingly driven during the machining operation and themolding rolls move transversely towards the workpiece and machining iscompleted when the molding rolls and the axis of the workpiece are inone plane. This end position is normally reached after 15 to 30rotations of the workpiece.

[0004] If different threads and threads of different diameters are to bemade it requires to exchange the molding rolls or to change the spacingof the molding rolls from each other by displacing the lever arms viasuitable adjusting screws with each associated lever arm beingassociated with an adjusting screw.

[0005] The Fette company journal “VerstellbarerTangential-Rollkopfhalter für NC-und CNC-Drehautomaten” has made known arolling head holder in which a clamping bolt can be fastened in a recessof the basic body with the bolt, in turn, accommodating a spring steelsheet in a recess. The spring steel sheet is fixed in the clamping boltby means of a clamping sleeve. The spring steel sheet is fork-shapedoutside the clamping bolt and interacts with a spindle traversing thelever arms. The spring steel sheet has the function of maintaining theadjusted axial position of the molding rolls and to yield if therelative orientation of the workpiece and the molding rolls is notcentral. Since a relative displacement occurs with respect to the holderif the levers carrying the molding rolls are pivoted the spring steelsheet is of a fork shape in order to compensate the different positions.

[0006] Now that the speeds of NC machines and rolling heads increasemore and more high torques result during the start-up and stop, whichcauses the spring steel sheet to get under a significant load. Thus,ruptures occur again and again, which interrupts the production process.

[0007] The object of the invention is to provide a tangential rollinghead in which the holder maintains its function even in case of a highload.

BRIEF SUMMARY OF THE INVENTION

[0008] The sheet metal element is of a rigid design in the invention.Thus, it is intended not to bend at all or only in a negligible mannerif the annular groove effects a relative motion with respect to thesheet metal element. Rather, disc springs are located on the two sidesof the sheet metal element adjacent to the recess, which makes the sheetmetal element more or less pivotable as a whole if a deflection from thecentral position should become necessary.

[0009] The invention not only helps in keeping the rolling head in aposition central to the tool if the distance of the rolling head axis isvaried, but we will also obtain a spring action for the case that thetool is not central towards the rolling head. The spring load isabsorbed by the disc springs which have a long service life. Arelatively small change of the angle is achieved for the spring metalsheet, thus avoiding any tilt in the spindle groove.

[0010] The tangential rolling head of the invention, as known rollingheads do as well, obtains a balance in length if the distance of theaxis is varied in the rolling head.

[0011] There is no fixed connection between the rolling head and thebasic body. Therefore, the rolling head may be removed from the holderin a simple way, e.g. for a roller change, settings by a gauge, etc.When the rolling head is inserted the sheet metal element will engagethe spindle groove without any aid.

[0012] Another specific advantage is that the inventive holder for thetangential rolling head is built very compactly. The space which is leftvacant as compared to conventional rolling heads may be utilized forfastening different types.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0013] An embodiment of the invention will now be explained in moredetail with reference to the drawings.

[0014]FIG. 1 shows a tangential rolling head of the invention alonglines 1-1 of FIG. 2, partly in a side view, partly in a section,

[0015]FIG. 2 shows a plan view of the tangential rolling head of FIG. 1,shows an insert piece with a sheet metal element of the tangentialrolling

[0016]FIG. 3 head of FIGS. 1 and 2,

[0017]FIG. 4 shows the assembly of FIG. 3 in a perspectiverepresentation.

DETAILED DESCRIPTOIN OF THE INVENTION

[0018] While this invention may be embodied in many different forms,there are described in detail herein a specific preferred embodiment ofthe invention. This description is an exemplification of the principlesof the invention and is not intended to limit the invention to theparticular embodiment illustrated.

[0019] The rolling head 10 illustrated in FIGS. 1 and 2 has a basic body12 which is provided with two forked arms 14, 16 as well as a shank 18projecting transversely therefrom, which is loaded into a machine toolwhich is not shown. The rolling head 10 further has two levers 20, 22the front lever arm 24, 26 of which supports a molding roll 28 and 30which are at a predetermined spacing from each other. The levers 20, 22are pivotally supported about a gudgeon 32 which extends through the twoforked arms 14, 16. To such an extent, the tangential rolling headdescribed is the state of the art. No detailed reference will be made tohow to actuate the molding rolls 28, 30 during the forming process.

[0020] The rear lever arms 34, 36 are traversed by a spindle 38. Thelever arms 34, 36 have threaded bores (not shown) which mate withthreaded portions of the spindle 38 (not shown either) with the threadedportions being in an opposite sense so that if the spindle is rotatedthe molding rolls 28, 30 are either moved towards each other or awayfrom each other depending on the sense of rotation of the spindle 38.

[0021] The spindle has an annular groove (not shown either) which isapproximately central and interacts with a fork-like portion of a sheetmetal element 40 which will be described farther below. The annulargroove is at the level of the axis 42 which represents the middlebetween the molding rolls 28, 30. If this spacing is varied it isimportant that each roll 28, 30 be displaced by the same amount each toavoid varying the central position of the molding rolls 28, 30 becausethis would otherwise cause the axes to be shifted with respect to theworkpiece.

[0022] The forked portion of the sheet metal element 40 can be seen fromFIG. 4. It is designed so as to fittingly engage the annular groove (notshown) of the spindle 38 as was mentioned already. The sheet metalelement 40, which is designed to be relatively thick and, thus, to bevery rigid, has a fastening portion 46 which has a through bore 48. Thefastening portion 46 is seated in a recess 50 of an insert piece 52. Theinsert piece 52 is cylindrical as can be seen from FIG. 4 and has adiametrically extending through bore 54 into which a pin 56 is fitted.The pin 56 extends through the bore 58 of the fastening part of portion46. Either side of the sheet metal element 40 has arranged thereon discspring packs 58, 60 via which the sheet metal element 40 is supported onthe upper and lower sides of the recess 40. As is apparent from FIG. 1the insert piece 52 is received in an appropriate recess 62 of the basicbody 12 and is located there by means of a stud 64.

[0023] If there is an eccentricity between the workpiece and the moldingrolls 28, 30 the lever arms 20, 22 will be jointly pivoted to a slightdegree, which causes the annular groove to move axially, thus pivotingthe sheet metal element 40. However, this swing is minimal so that nojamming will occur in the annular groove. The abrupt loads acting duringthe start-up and stop of the machine tool may be absorbed by the discspring packs 58, 60 in a simple way.

[0024] The above Examples and disclosure are intended to be illustrativeand not exhaustive These examples and description will suggest manyvariations and alternatives to one of ordinary skill in this art. Allthese alternatives and variations are intended to be included within thescope of the attached claims. Those familiar with the art may recognizeother equivalents to the specific embodiments described herein whichequivalents are also intended to be encompassed by the clams attachedhereto.

1. A tangential rolling head with a basic body including means forloading it into a machine tool, two two-armed levers pivotally supportedabout a common axis of the basic body one lever arm of which istraversed by a former roll and the other lever arm of which is traversedby a spindle which has a circumferential annular groove, a sheet metalelement which has a forked portion and a fastening portion wherein theforked portion engages the annular groove and the fastening portion isadapted to be fastened in a recess of the basic body by means of a pin,characterized in that the sheet metal element (40) is rigidly formed andis supported in the recess (50) on the two sides by means of discsprings (58, 60) slid onto the pin (56).
 2. The tangential rolling headaccording to claim 1, characterized in that the recess (50) is formed ina separate insert piece (52) which is adapted to be fastened in afurther recess (62) of the basic body (12).
 3. The tangential rollinghead according to claim 2, characterized in that the insert piece (52)is adapted to be fastened in the further recess (62) by means of a pin(64).
 4. The tangential rolling head according to claim 3, characterizedin that the insert piece (52) is of a cylindrical shape and that thefurther recess (62) is of a complementary shape.
 5. The tangentialrolling head according to claim 1, characterized in that the spindle(38) has opposite-sense threaded portions which engage threaded boreportions of the other lever arms (34, 36) for a self-adjustment of themolding rolls (28, 30) from each other upon rotation of the spindle(38).